private MediaFormat mediaFormat;
private MediaCodec mediaCodec;
private MediaCodec.BufferInfo info;
private Surface surface;//这个是OpenGL渲染的Surface

/**
 * 初始化MediaCodec
 *
 * @param codecName
 * @param width
 * @param height
 * @param csd_0
 * @param csd_1
 */
public void initMediaCodec(String codecName, int width, int height, byte[] csd_0, byte[] csd_1) {
        try {
          if (surface != null) {
                String mime = VideoSupportUtil.findVideoCodecName(codecName);
                mediaFormat = MediaFormat.createVideoFormat(mime, width, height);
                mediaFormat.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, width * height);
                mediaFormat.setByteBuffer("csd-0", ByteBuffer.wrap(csd_0));
                mediaFormat.setByteBuffer("csd-1", ByteBuffer.wrap(csd_1));
                MyLog.d(mediaFormat.toString());
                mediaCodec = MediaCodec.createDecoderByType(mime);
                info = new MediaCodec.BufferInfo();
                if(mediaCodec == null) {
                    MyLog.d("craete mediaCodec wrong");
                    return;
                }
                mediaCodec.configure(mediaFormat, surface, null, 0);
                mediaCodec.start();
          }
        } catch (Exception e) {
            e.printStackTrace();
        }
    } 
}

image

VideoSupportUtil.java

import android.media.MediaCodecList;

import java.util.HashMap;
import java.util.Map;

public class VideoSupportUtil {

    private static Map<String, String> codecMap = new HashMap<>();
    static {
        codecMap.put("h264", "video/avc");
    }

    public static String findVideoCodecName(String ffcodename){
        if(codecMap.containsKey(ffcodename))
        {
            return codecMap.get(ffcodename);
        }
        return "";
    }

    public static boolean isSupportCodec(String ffcodecname){
        boolean supportvideo = false;
        int count = MediaCodecList.getCodecCount();
        for(int i = 0; i < count; i++){
            String[] tyeps = MediaCodecList.getCodecInfoAt(i).getSupportedTypes();
            for(int j = 0; j < tyeps.length; j++){
                if(tyeps[j].equals(findVideoCodecName(ffcodecname))){
                    supportvideo = true;
                    break;
                }
            }
            if(supportvideo){
                break;
            }
        }
        return supportvideo;
    }
}

c++层:

const char* codecName = ((const AVCodec*)avCodecContext->codec)->name;
onCallInitMediacodec(
                codecName,
                avCodecContext->width,
                avCodecContext->height,
                avCodecContext->extradata_size,
                avCodecContext->extradata_size,
                avCodecContext->extradata,
                avCodecContext->extradata
        );

//获取jmid_initmediacodec
jclass  jlz = jniEnv->GetObjectClass(jobj);
jmethodID jmid_initmediacodec = env->GetMethodID(jlz, "initMediaCodec", "(Ljava/lang/String;II[B[B)V");

//在子线程
void onCallInitMediacodec(const char* mime, int width, int height, int csd0_size, int csd1_size, uint8_t *csd_0, uint8_t *csd_1) {

    JNIEnv *jniEnv;
    if(javaVM->AttachCurrentThread(&jniEnv, 0) != JNI_OK)
    {
        if(LOG_DEBUG)
        {
            LOGE("call onCallComplete worng");
        }
    }

    jstring type = jniEnv->NewStringUTF(mime);
    jbyteArray csd0 = jniEnv->NewByteArray(csd0_size);
    jniEnv->SetByteArrayRegion(csd0, 0, csd0_size, reinterpret_cast<const jbyte *>(csd_0));
    jbyteArray csd1 = jniEnv->NewByteArray(csd1_size);
    jniEnv->SetByteArrayRegion(csd1, 0, csd1_size, reinterpret_cast<const jbyte *>(csd_1));

    jniEnv->CallVoidMethod(jobj, jmid_initmediacodec, type, width, height, csd0, csd1);

    jniEnv->DeleteLocalRef(csd0);
    jniEnv->DeleteLocalRef(csd1);
    jniEnv->DeleteLocalRef(type);
    javaVM->DetachCurrentThread();

}

解码AvPacket数据

public void decodeAVPacket(int datasize, byte[] data) {
    if (surface != null && datasize > 0 && data != null) {
        int intputBufferIndex = mediaCodec.dequeueInputBuffer(10);
        if (intputBufferIndex >= 0) {
            ByteBuffer byteBuffer = mediaCodec.getOutputBuffers()[intputBufferIndex];
            byteBuffer.clear();
            byteBuffer.put(data);
            mediaCodec.queueInputBuffer(intputBufferIndex, 0, datasize, 0, 0);
        }
        //这里拿到outputBufferIndex然后就可以获取到数据,这里会通过surface达到渲染
        int outputBufferIndex = mediaCodec.dequeueOutputBuffer(info, 10);
        while (outputBufferIndex >= 0) {
            mediaCodec.releaseOutputBuffer(outputBufferIndex, true);
            outputBufferIndex = mediaCodec.dequeueOutputBuffer(info, 10);
        }
    }
}

c++层回调decodeAVPacket

datasize = avPacket->size;
data = avPacket->data;//jni这里需要把uint8_t转为jbyteArray，类似初始化那